<body>
<table height="400" border="1"><tr><td valign="bottom" align="center">
vertical and horizontal centered table cell.
<div style="width: 300px; height: 150px; border: blue solid;">
300x200 div in table
</div>
<table border="1" height="150"><tr><td>
nested table
</td></tr>
</table>
</td></tr></table>
<div style="text-align: center; border: red solid;">
div with text-align: center
<div style="width: 300px; height: 200px; border: blue solid;">
nested 300x200 div 
</div>
</div>

</body>